In general, a surface treatment is to make a surface of a product made of a material such as a metal look good, or to improve a surface to have heat resistance, corrosion resistance, abrasion resistance, etc. so that a function of the product can be improved according to a condition of usage of the product. That is, the surface treatment is concealing inner defects, etc. by properly treating a surface of the metal.
The surface treatment includes plating on a surface of an accessory, chromium plating on brass, or a tinplating for iron sheet, etc.
The surface treatment methods include alumite for protecting an inside of an object of surface treatment by making oxide film, an anticorrosive coating by paint, a chemical vapor deposition (CVD) reaction, or a physical vapor deposition (PVD) reaction.
In the meantime, a heat exchanger used in an air conditioner, a refrigerator, a heating apparatus, etc. is a device for transferring heat from fluid of high temperature to fluid of low temperature through a heat transfer wall. At this time, a flow of the fluid becomes different according to a characteristic of a surface of the heat transfer wall, and the characteristic of the surface of the heat transfer wall greatly influences to a heat exchange efficiency of the heat exchanger.
Accordingly, a radiator surface of the heat exchanger is required to have a surface treatment having various characteristics according to a performance of the heat exchanger. To this end, fins of the heat exchanger are fabricated by processing a sheet having a treated surface to improve hydrophilicity, hydrophobicity, or corrosion resistance.
Also, the sheet for processing the fins of the exchanger has a surface treatment that forms a deposition layer at the surface of the sheet by using the chemical vapor deposition reaction or the physical vapor deposition reaction.
In the meantime, for the surface treatment, reaction gas is injected in a deposition chamber and then power is applied thereto for a deposition reaction. A method for applying power includes a method for applying power to the object of surface treatment for the deposition reaction.
In the conventional surface treatment method represented in PCT Publication No. WO9927157, power is directly applied to an object of surface treatment in a polymerization chamber injected by reaction gas to cause a plasma polymerization reaction, thereby forming a deposition layer at a surface of the object of surface treatment.
However, in said method, a deposition reaction in the deposition chamber, a formation of a deposition layer, and a characteristic of the formed deposition layer are greatly influenced by the method for applying power to the object of surface treatment.
Especially in case that the object of surface treatment is treated with a large number of quantity, a power has to be properly applied to the object of surface treatment without influencing to the deposition reaction or the deposition layer formed at the surface.
In the meantime, a product requiring the surface treatment is processed according to condition or shape and then fabricated after the surface treatment. At the time of said processing, a cut surface or the deposition layer can be damaged and another member having no surface treatment can be generated.
That is, when the objects of which surfaces are treated with a large number of quantities in order to have required characteristics processed by molding or assembling, the surfaces can be damaged. Also, other members without required characteristics can reduce effects of the surface treatment.